Usefulness of the integrated concentration of growth hormone (GH) as a diagnostic aid in children with growth disorders will be investigated. This will be done by withdrawing serum for GH determination every 20 minutes from an indwelling heparin loch for either 12 or 24 hours (depending on the child's size) in children with abnormalities of growth. These data will then be compared with normative data being compiled under a separate protocol.